Recent content by Rorshach

Homework Statement Hello, I have a problem with a quote from a textbook I am currently reading, and it is not strictly a homework problem. It is a part of the book in which authors explain mechanism of sound amplification in human ear, specifically by resonance in ear canal and mechanical...

Hello! I am looking for a good handbook in the acoustics field. I read that handbook of acoustics by Malcolm J. Crocker is one of the best, second one that came up in my research is master handbook of acoustics by Everest & Pohlmann. Can anyone recommend one over the other, or maybe knows...

I mean the general formula for this would be: SPL = G - ΔSPL where G is a given value of SPL at a given distance. and all the signs in the formula are the same, only values of SPL, G and ΔSPL change and can be negative or positive, right?

I still don't understand how I'm supposed to get SPL = 115 + 10log(0.22/1) In the first equation it was very intuitive, and produced expected result. But second equation just makes no sense: in the logarithm (just like authors state in the book is 10log, because two powers are being compared)...

but here we are dealing with pressure, and it would have to be SPL = 115 + 10log(0.22/1) for the correct result- how do I correlate power and pressure correctly?

that is right. I have a question: When should it be minus sign and when should it be plus? What determines that?

I am sorry, in that case it was my typo. In the book it stands 20log(6.1). It's the second equation that doesn't work out. I made sure it is exactly like in the textbook, so no typo there.

55 dB = 20log(p1/pref) 55 = 20log(p1/20*10-6) 2.75 = log(p1/20*10-6) 102.75 = p1/20*10-6 p1 = 102.75 * 20*10-6 p1 = 0.01 Pa r1 = 84 ft r2 = 118.7 ft p∝1/r p1 = k/r1 p2 = k/r2 p2 = p1 * r1/r2p2 = p1 * r1/r2 p2 = 0.01 Pa * 84/118.7 = 0.007 Pa SPL2 = 20log(0.007/(20*10-6)) = 50.881 ≈ 51 dB

This is a simple problem from a textbook I am reading, and everything below is written word by word and sign by sign from said textbook. Formulas given in the book just don't give the result authors claim they do: Homework Statement An input of 1 W produces a SPL of 115 dB at 1 m. What is the...

Ok, I will. Thank You for your help- I have one question regarding the approach You suggested. The results from method proposed in the book (52 dB) differ slightly from the one You proposed(~51dB). Is it ok? I mean, the dependence of acoustic pressure on distance is not a strict rule, but more...

Yes, You are right. There is also one more problem- an easy one, about loudspeaker SPL.In the book they give the solution, but when I checked it on calculator, the results were different. Results they gave were intuitive, but formulas they used give completely different result. Do You think I...

I understood it some time ago, sorry for not responding for so long- did You mean this approach: p ∝ 1/r p1 ∝ 1/r1 p2 ∝ 1/r2 p2/p1 = r1/r2 p2 = p1 * r1/r2 SPLreflected = 20log10(preflected/preference)

Sorry for not replying for so long- my laptop had a severe malfunction of graphics card after windows 10 update. Sound pressure decreases with 1/r at a distance from sound source.

I am sorry, but I still don't understand it. Maybe one of my brain cells is locked, but the the second, and especially the third question and their solutions are not understandable to me. Why the "delay" is not 105 msec? That question is constructed in such a way that it leaves no option but to...

I wrote everything down word for word from my book. I am barely on page 30 and so far there have been few questionable equations, but those two just boggle me. Under every question there are equations and small adnotations for what is being done to solve the problem, so I will write entire...